Apparatus and method for subgrade preparation

Abstract

A subgrade preparation apparatus for preparing a subgrade surface for concrete to be placed thereon includes a base unit positionable on a support surface adjacent to a targeted subgrade area, an extendable boom extending from the base unit, and a subgrade head assembly adjustably mounted on the extendable boom. The subgrade head assembly includes a framework, a plow and a material moving device for moving material toward at least one side of the subgrade head assembly. The subgrade head assembly includes a plow end plate movably attached at an outer end of the plow and movable to a position where the plow end plate is generally vertical and forms an end portion of the plow to limit plowed material from flowing around the outer end of the plow as the subgrade head assembly is moved over and along the subgrade surface at the targeted subgrade area.

1. A subgrade preparation apparatus for leveling, grading and compacting a subgrade surface for receiving concrete thereon, said subgrade preparation apparatus comprising:
 a base unit positionable on a support surface adjacent to a targeted subgrade area; 
 a support boom extending from said base unit; and 
 a subgrade head assembly adjustably mounted on said support boom, said subgrade head assembly being vertically adjustable relative to said support boom to be lowered onto a subgrade surface at the targeted subgrade area, said subgrade head assembly including a framework, a plow and a material moving device for moving material toward at least one side of said subgrade head assembly for establishing the subgrade surface, said plow having a longitudinal axis and an outer end, said subgrade head assembly including a plow end plate pivotally attached at said outer end and pivotable about a generally horizontal pivot axis that is generally transverse to a longitudinal axis of said plow, said plow end plate being pivotable between a raised postion, where said plow end plate is generally horizontally oriented and generally transverse to said longitudinal axis of said plow, and a lowered position, where said plow end plate is generally vertical and is positioned at said outer end of said plow and generally transverse to said longitudinal axis of said plow to form an end portion of said plow to limit plowed material from flowing around said outer end of said plow as said subgrade head assembly is moved over and along the subgrade surface at the targeted subgrade area. 
 
   
   
     2. The subgrade preparation apparatus of  claim 1  including first and second plow end plates pivotally mounted at respective ends of said main plow and pivotable about respective generally horizontal pivot axes. 
   
   
     3. The subgrade preparation apparatus of  claim 1 , wherein said material moving device comprises an auger having a longitudinal rotatable portion rotatably mounted to said subgrade head assembly. 
   
   
     4. The subgrade preparation apparatus of  claim 1  including an elevation device which is operable to lower and raise said subgrade head assembly relative to said support boom and said base unit. 
   
   
     5. The subgrade preparation apparatus of  claim 4 , wherein said elevation device is operable in response to a laser reference plane and laser receivers mounted to a portion of said elevation device. 
   
   
     6. The subgrade preparation apparatus of  claim 4 , wherein said elevation device is operable in response to a three dimensional profiler or contouring system mounted to a portion of said elevation device. 
   
   
     7. The subgrade preparation apparatus of  claim 1 , wherein said subgrade head assembly is pivotally mounted to said support boom and is pivotable about a generally vertical axis. 
   
   
     8. The subgrade preparation apparatus of  claim 7 , wherein said generally vertical pivot axis is offset from a center of said subgrade head assembly and is positioned toward one end of said subgrade head assembly. 
   
   
     9. The subgrade preparation apparatus of  claim 7 , wherein said subgrade head assembly includes a mounting structure that is pivotally mounted to said support boom and wherein said plow, said material moving device and said plow end plate being vertically adjustable relative to said mounting structure via an elevation device. 
   
   
     10. The subgrade preparation apparatus of  claim 9 , wherein said material moving device is vertically adjustable relative to said plow. 
   
   
     11. The subgrade preparation apparatus of  claim 1 , wherein said subgrade head assembly is removably attached to said support boom and is removable therefrom, said support boom being configured to attach to a concrete screeding head assembly when said subgrade head assembly is removed therefrom. 
   
   
     12. A method for leveling, grading and/or compacting a subgrade surface for receiving concrete on the subgrade, said method comprising:
 providing a subgrade preparation apparatus comprising a base unit positionable on a support surface and a subgrade head assembly having a plow which defines at least one end, said subgrade head assembly including a plow end plate movably mounted at said at least one end of said plow; 
 vertically moving said subgrade head assembly relative to said base unit onto a subgrade area; 
 pivoting said plow end plate about a generally horizontal pivot axis to move said plow end plate from a generally horizontal orientation to a generally vertical orientation along said end of said plow and generally transverse to a longitudinal axis of said plow; 
 generally horizontally moving said subgrade head assembly along the subgrade; 
 establishing the subgrade surface with said plow and a means for moving material to one side of said subgrade head assembly; and 
 limiting movement of plowed material around said end of said plow by said generally vertically oriented plow end plate as said subgrade head assembly is moved over and along the subgrade surface. 
 
   
   
     13. The method of  claim 12 , wherein said subgrade head assembly includes a plow end plate that is pivotably mounted at each of said ends of said plow, and wherein said method comprises pivoting one of said plow end plates about a respective generally horizontal pivot axis to move said plow end plate to a generally vertical orientation along the respective end of said plow. 
   
   
     14. The method of  claim 12  including pivoting said subgrade head assembly about a generally vertical pivot axis so that one end of said plow is a leading end and the other end of said plow is a trailing end as said subgrade head assembly is moved over and along the subgrade surface. 
   
   
     15. The method of  claim 14 , wherein said subgrade head assembly includes a plow end plate that is pivotably mounted at each of said ends of said plow, and wherein pivoting said plow end plate comprises pivoting said plow end plate about said generally horizontal pivot axis to move said plow end plate to said generally vertical orientation at said trailing end of said plow. 
   
   
     16. The method of  claim 14 , wherein said generally vertical pivot axis is spaced from a center of said subgrade head assembly and is positioned toward one end of said subgrade head assembly. 
   
   
     17. The method of  claim 12 , wherein vertically moving said subgrade head assembly includes vertically moving said subgrade head assembly in response to a laser reference plane and laser receivers mounted to a portion of said subgrade head assembly. 
   
   
     18. The method of  claim 12 , wherein vertically moving said subgrade head assembly includes vertically moving said subgrade head assembly in response to a three dimensional profiler or contouring system mounted to a portion of said subgrade head assembly. 
   
   
     19. The method of  claim 12  including:
 removing said subgrade head assembly from said subgrade preparation apparatus after preparation of the subgrade surface; 
 mounting a concrete screeding head assembly to said subgrade preparation apparatus; and 
 screeding uncured concrete placed at the prepared subgrade surface. 
 
   
   
     20. A subgrade preparation head assembly configured to adjustably mount to a subgrade preparation apparatus for leveling, grading and compacting a targeted subgrade surface for receiving concrete thereon, said subgrade preparation head assembly comprising:
 a framework; 
 a plow mounted to said framework, said plow having an outer end; 
 a material moving device mounted to said framework, said material moving device being operable to move material toward at least one side of said subgrade head assembly; and 
 a plow end plate pivotally attached at said outer end of said plow and being pivotable about a generally horizontal pivot axis between a raised position, where said plow end plate is generally horizontally oriented, and a lowered position where said plow end plate is generally vertical and is positioned at said outer end of said plow and is generally transverse to the longitudinal direction of the plow so as to form an end portion of said plow to limit plowed material from flowing around said outer end of said plow as said subgrade head assembly is moved over and along the subgrade surface at the targeted subgrade area. 
 
   
   
     21. The subgrade preparation head assembly of  claim 20  including first and second plow end plates movably mounted at respective ends of said plow and pivotable to said lowered position. 
   
   
     22. The subgrade preparation head assembly of  claim 20  including an elevation device which is operable to lower and raise said framework relative to a support structure. 
   
   
     23. The subgrade preparation head assembly of  claim 20 , wherein said subgrade head assembly is pivotally mountable to a support structure and is pivotable about a generally vertical axis, said generally vertical pivot axis being offset from a center of said subgrade head assembly and positioned toward one end of said subgrade head assembly. 
   
   
     24. The subgrade preparation head assembly of  claim 20 , wherein said plow end plate is generally transverse to said longitudinal axis of said plow when in said raised position.